PETER TAYLOR thought he had got away with the perfect murder when he killed his wife, Monica.

So sure was he that when, nine years later, his daughter's marriage ran into difficulties, he thought he would get away with plotting the murder of her husband. But this time the hotelier was trapped when he recruited two undercover detectives in his bid to get rid of his son-in-law.

As police, who had always been suspicious about Mrs Taylor's disappearance, delved into the background, Taylor found what happened nearly a decade before returning to haunt him.

What neither Taylor nor his daughter realised was that Derek and Martin were undercover detectives and their conversations had been recorded. Within minutes, father and daughter were arrested.

The murder attempt also produced fresh evidence about the disappearance of Monica. Taylor told one of the detectives about it not being the first time. Police had always been suspicious about what had happened to the neat, tidy punctilious woman who had simply disappeared. Her son, Graham, had married a cousin of Rosa's and she had been looking forward to visiting them in Venezuela.

Taylor, described by Chief Superintendent John Homer as a 'cool, callous, calculating man', at one point suggested his wife might be living in the United States. In fact, in 1984, Louis Matthews, after being arrested for a burglary, asked police why they were wasting time on a trivial matter 'when there are people getting away with murder'.

He then revealed the approach Taylor had made but when it was put to Taylor that he had offered pounds 500 to have his wife killed, the hotelier dismissed this as 'rubbish' and there was insufficient evidence to proceed.

Detectives say there is nothing to suggest Taylor's daughter knew what had happened to her mother. Friends say she believed Mrs Taylor had killed herself.

The police investigation has been a long one and there are still outstanding questions. How was Monica killed? Where is her body?

Police have considered the possibility that she was disposed of in an acid bath after Taylor spoke of getting rid of animals in acid.

Detectives have also considered the possibility that the body could have been dropped into a mine shaft in Cornwall.